I'm saying that if you believe there is no all-loving, all-knowing, etc god/force/nature to the world, then just live whatever your best ideals are. Love, goodness, selfishness, hate, rage at a bullshit god - it doesn't matter. Each will fail. But the experience of living that ideal, consciously, is valuable.

"It" is the ideal, or principle, or perspective you live by, and invest your time and energy into. But I don't think you need to do something specific. I don't think a person can intentionally let something go until they've lived enough of it, and that can't really be rushed or stopped.